There have been developed and marketed a wide variety of meat and poultry thermometers adapted to be inserted prior to cooking and to indicate the degree of cooking by the internal temperature of the meat or poultry. An advancement in this field is the disposable poultry thermometer having an indicating rod or stem that is visually movable. One kind of disposable thermometer of this general type is the pop-up thermometer which generally incorporates a heat fusible latch to retain a spring loaded plunger or the like within a thermometer barrel so that upon attainment of a predetermined thermometer temperature the latch is released and the rod or plunger pops up to indicate completion of cooking. An alternative type of disposable cooking thermometer as shown in U.S. Pat. No. 3,759,103 includes an indicating rod or the like extending from the thermometer barrel and movable into the barrel under spring pressure as a material within the thermometer softens with increasing temperature.
The present invention comprises an improvement in the structure of the latter type of disposable cooking thermometers particularly with regard to latching of the indicating stem or rod in storage position of the thermometer.